Autoimmunity in patients with inborn errors of immunity: A case series

To assess the prevalence of systemic and organ-specific autoimmunity among individuals with human inborn errors of immunity (IEI).

Retrospective study. We recorded demographic variables, type of immunodeficiency, and systemic and organ specific autoimmunity.

We included 48 patients (54.1% men) with mean age of 32.1 years. The most common IEIs included combined immunodeficiency with syndromic features (31.2%) and predominantly antibody deficiency (20.1%). We observed autoimmunity in 15 patients (31.2%): 12 organ-specific autoimmunity and 5 systemic autoimmunity, not mutually exclusive groups. Organ-specific autoimmunity preceded the onset of IEI in 5 patients, was concurrent in one patient, and developed after the diagnosis of IEI in 6 cases. From the systemic autoimmunity group, we observed polyarteritis nodosa (n = 2), antiphospholipid syndrome (APS) (n = 2), and overlap of limited systemic sclerosis/APS/Sjögren's syndrome (n = 1), and in all cases, this occurred after the IEI diagnosis.

Our findings confirm the coexistence of autoimmunity and IEI. This overlap may be attributed to B and T cell disorders, as well as potential alterations in the microbiota in these patients.